Costly Flaws Found In Navy's Top Jet




 
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Costly Flaws Found In Navy's Top Jet
 
May 17th, 2007  
Team Infidel
 
 

Topic: Costly Flaws Found In Navy's Top Jet


Costly Flaws Found In Navy's Top Jet
Boston Globe
May 17, 2007
Pg. 1

Wing mechanism wear could halve flight hours
By Bryan Bender, Globe Staff
WASHINGTON -- Engineers have uncovered a flaw in the Navy's top fighter jet that could reduce by half the aircraft's advertised service life and potentially cost taxpayers hundreds of millions of dollars in repairs, according to Pentagon documents and military and industry officials.
A mechanism inside the wings of the F/A-18 Super Hornet, manufactured by Boeing Co., is wearing out prematurely, prompting the Navy to order the company to make changes in the plane's production as well as retrofit several hundred planes already operating off the decks of Navy aircraft carriers, according to a Navy official.
Officials stressed that they are not considering whether to ground the workhorse jet, because the problem does not affect its operation. Still, the "fatigue life issue," if uncorrected, would drastically shorten the $50 million aircraft's life span from 6,000 flight hours to 3,000 hours, the documents warn.
"Through testing of Super Hornets they discovered there is a fatigue issue on part of the inside of one of the wings," a Navy official confirmed in a statement yesterday. "From here on out every aircraft will be made so they don't have the problem." The official said at least 193 planes now in service will be retrofitted beginning in 2010. The plane was introduced in 1999.
But the wing is apparently not the only thing that needs to be retrofitted, according to the Navy official, who asked not to be named because he is not authorized to speak for the program. The Navy did not comment officially about the problem despite numerous requests.
The current fleet of Super Hornets is slated to receive a total of 40 modifications, both major and minor; additionally, a separate problem with the aircraft's wing flaps could limit even further the plane's ability to fly safely, the documents show. Special fatigue tests now underway to identify a fix for the second wing problem are set to be completed in July.
Navy officials said they will not know the price tag for retrofitting the wings until an "engineering change proposal" outlining solutions is completed in the coming months.
Loren Thompson, a defense analyst at the Lexington Institute, a defense and public policy think tank, said any structural problem in the jet's wing "is a much bigger problem" that will require expensive, time-consuming repairs.
"It would be very costly to go back and refit" the jets, Thompson said. "Usually, if there is fatigue or corrosion problems [on aircraft wings], it is [on] the outside part that is exposed to the elements. When you develop a fatigue problem inside the wing, the challenge of fixing it grows.
"The cost, the man hours, the time the aircraft are out of service: No matter how you want to measure it, it is not minor."
The Navy plans to build 210 Super Hornets over the next five years. Ninety of the planes will be outfitted with advanced radar and high-tech sensors to jam enemy electronics. That version, known as the Growler, is awaiting approval to begin initial production next year.
Australia recently signed a $2.4 billion deal to purchase 24 Super Hornets, the first sale in what Boeing hopes will be a growing foreign market for the aircraft.
The structural problem in the wings has emerged at a time when Boeing has proposed selling the Navy at least 100 more Super Hornets in case the F-35 Joint Strike Fighter -- the Pentagon's next-generation attack jet now under development -- is delayed further, according to news reports. The F-35, produced by Boeing rival Lockheed Martin, is not expected to enter service for eight years.
The Super Hornet is 25 percent larger than its predecessor, which was first widely introduced in the 1980s. Considered one of the Pentagon's most complex aircraft, the Super Hornet became the Navy's mainstay jet after the infamous A-12 stealth aircraft project -- launched to replace the aging, earlier-model Hornets -- collapsed.
Some critics argue that the design changes and upgrades in the latest generation Hornets were so significant that the Super Hornet project should have been scrutinized as though it were an entirely new aircraft line -- rather than the more cursory look reserved for modifications of earlier-model aircraft.
"They never built a prototype," said James P. Stevenson, a military aircraft specialist and author of "The Pentagon Paradox," which reserves a chapter for the F/A-18 program. "After 25 years of development they still haven't got it right."
Indeed, the F/A-18 program has had a series of aerodynamic and structural problems over the years. As far back as the early 1980s, the first versions of the Hornets also had problems with premature wear and tear on the airframe, requiring significant retrofitting.
Those structural issues have been more pronounced with the Super Hornet.
For example, testing of the Super Hornet in the late 1990s revealed that the plane would "flutter" during certain maneuvers -- a flaw that nearly brought the program to a standstill. It required the Navy and Boeing to make substantial changes to the wings and pylons.
Yet while those adjustments made the flutter "manageable," according to the new documents, it produced a new problem: accelerated wear on some of the missiles carried under the wings, according to the documents.
Now, the Navy and Boeing are scrambling to come up with a solution for the Super Hornet's wing fatigue, which first showed up in tests in 2005, the Navy official said.
The prediction that the flaw could drastically cut the jet's anticipated life pan amazed some defense analysts .
"That would be a significant decrease," said Richard Aboulafia, a defense analyst at the Teal Group in Fairfax, Va.
Still, the documents indicate the Navy and Boeing are confident they know how to fix the problem. A proposal "that will address the inter-wing retro fit" is expected within a few months, according to a document prepared by Naval Air Systems Command and provided to the Globe. "Not until 2008 will aircraft roll off the line with full life" if Boeing makes the necessary adjustments to its production, according to the document.
 


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